1. Field of the Invention
The present invention related to mattresses, specifically to quilted mattress covers and methods of making same.
2. Background of the Invention
Mattresses with quilted mattress covers are well-known in the art. For example, U.S. Pat. No. 5,896,605 describes a conventional mattress construction with an inner coil spring unit surrounded on the top and bottom by padding which provides a barrier and cushion against the metal springs. An additional wire grid is further provided as a barrier between the padding and the spring unit. The unit is then padded on its top and bottom by layers of foam, cotton, and other materials. The typical outer construction of a mattress includes a top and bottom cover panel and a border which surrounds the four sides or perimeter of the spring unit. The panels and border are usually quilted fabric available in a variety of colors and print patterns, thus providing the initial aesthetic appeal to the customer.
A flange formed by a strip of strong fabric is attached to the boundaries or peripheries of the top and bottom panels prior to the final assembly of the mattress. The top and bottom flanges extend over the side edges of the spring unit and are anchored to the springs using metal rings, commonly referred to as “hog rings.” The flanges fix the padded layers in place on the top and bottom of the spring unit, so that during prolonged use the various layers are not dislodged. The flanges also serve to resist the tensile forces around the perimeter of the bed resulting from a body resting on top of the mattress.
A specialized tape edge machine, mounted on a special table, is used to attach the border to the top and bottom covers after the flanges of the covers have been attached to the spring unit. Wads of cotton material are often inserted just prior to the covers' attachment in order to round and pad the corners of the mattress. Also, stiffening members may be affixed to upper and lower border wires (when such wires or rods are used) along the mattress sides prior to final assembly, for people who sit on the edge of the bed and require extra support therein.
In the final assembly of the mattress, a decorative tape or welting is folded over the outside edges of the panel, flange, and border materials by an operator. The operator must manually position the tape over the raw edges while walking backward, as the machine moves around the mattress and stitches the tape to form a welt around the finished side of the mattress perimeter. This is done for the top panel attachment to the border, and also for the bottom panel attachment to the border. The tape edge machine and its required components are quite costly, and a highly skilled operator is required to produce quality mattresses.
The components of a conventional mattress constructed as above are illustrated in FIG. 1. Layers of padding are placed between the cover panels 12, 14 and a coil spring unit 38, with the layers repeated in order on the unit's two finished (sleeping) surfaces. The mattress typically includes a foam pad 40, a cotton pad 42, a padding 44, and a grid 46 which is placed closest to springs 48 of the unit 38. Flanges 52 and 58 are secured to coil springs 48 (one shown) by hog rings 54.
A border 16 is attached to panels 12, 14 by welting 35 at seam 34 (on the top corner) and welting 35 at seam 36 (on the bottom corner) with its finished side facing outward. This attachment is typically made by stitching through the welting, border 16, flange 52 or 58, and cover panel 12 or 14 on the finished (customer-facing) side of the seam.
Padding 44 adds a cushioning layer and prevents the foam and cotton pads 40, 42 from becoming lodged in, or pushed through, the grid 46 and/or the springs 48.
The presence of welting 35 on seam 34 (i.e., on the top corner edge of the mattress) has often been cited as a cause of some discomfort by users. It is also known to trap dirt and crumbs. More significantly, the need to use a specialized tape edge machine, mounted on a special table, with the concomitant requirement for a specially skilled operator, increases production costs.
It would therefore be desirable to provide a mattress having a mattress cover without an outside welt, and a method of seaming such mattress cover without the need for a skilled operator and specialized equipment for assembly, such as a tape edge machine and/or a special table.